cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A174060 a(n) = Sum_{k=0..n} floor(sqrt(k))^2.

Original entry on oeis.org

0, 1, 2, 3, 7, 11, 15, 19, 23, 32, 41, 50, 59, 68, 77, 86, 102, 118, 134, 150, 166, 182, 198, 214, 230, 255, 280, 305, 330, 355, 380, 405, 430, 455, 480, 505, 541, 577, 613, 649, 685, 721, 757, 793, 829, 865, 901, 937, 973, 1022, 1071, 1120, 1169, 1218, 1267, 1316
Offset: 0

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Author

Keywords

Comments

Partial sums of A048760. - R. J. Mathar, Mar 31 2010

Crossrefs

Cf. A022554 (1st), this sequence (2nd), A363497 (3rd).
Cf. A363498 (4th), A363499 (5th), A048760.

Programs

Formula

a(n) = (1/6)*m*(6*m*n - (m+1)*(3*m^2+m-1)) with m = floor(sqrt(n)). - Yalcin Aktar, Jan 30 2012

A363497 a(n) = Sum_{k=0..n} floor(sqrt(k))^3.

Original entry on oeis.org

0, 1, 2, 3, 11, 19, 27, 35, 43, 70, 97, 124, 151, 178, 205, 232, 296, 360, 424, 488, 552, 616, 680, 744, 808, 933, 1058, 1183, 1308, 1433, 1558, 1683, 1808, 1933, 2058, 2183, 2399, 2615, 2831, 3047, 3263, 3479, 3695, 3911, 4127, 4343, 4559, 4775, 4991, 5334
Offset: 0

Views

Author

Hans J. H. Tuenter, Jun 05 2023

Keywords

Comments

Partial sums of the third powers of the terms of A000196.

Crossrefs

Sums of powers of A000196: A022554 (1st), A174060 (2nd), this sequence (3rd), A363498 (4th), A363499 (5th).

Programs

  • Mathematica
    Table[(n + 1) #^3 - (1/60) # (# + 1) (3 # - 1) (12 #^2 + 7 # - 4) &[Floor@ Sqrt[n]], {n, 0, 50}] (* Michael De Vlieger, Jun 10 2023 *)
  • PARI
    a(n) = sum(k=0, n, sqrtint(k)^3); \\ Michel Marcus, Jun 06 2023
    
  • Python
    from math import isqrt
    A363497 = [0]
    for n in range(1,50): A363497.append(A363497[-1] + isqrt(n)**3)
    print(A363497) # Karl-Heinz Hofmann, Jun 14 2023
    
  • Python
    from math import isqrt
    def A363497(n):return (m:=isqrt(n))**3*(n+1)-(m*(m+1)*(3*m-1)*(12*m**2+7*m-4))//60
    # Karl-Heinz Hofmann, Jun 14 2023

Formula

a(n) = (n+1)*m^3 - (1/60)*m*(m+1)*(3*m-1)*(12*m^2+7*m-4), where m = floor(sqrt(n)).

A363498 a(n) = Sum_{k=0..n} floor(sqrt(k))^4.

Original entry on oeis.org

0, 1, 2, 3, 19, 35, 51, 67, 83, 164, 245, 326, 407, 488, 569, 650, 906, 1162, 1418, 1674, 1930, 2186, 2442, 2698, 2954, 3579, 4204, 4829, 5454, 6079, 6704, 7329, 7954, 8579, 9204, 9829, 11125, 12421, 13717, 15013, 16309, 17605, 18901, 20197, 21493, 22789
Offset: 0

Views

Author

Hans J. H. Tuenter, Jun 05 2023

Keywords

Comments

Partial sums of the fourth powers of the terms of A000196.

Crossrefs

Sums of powers of A000196: A022554 (1st), A174060 (2nd), A363497 (3rd), this sequence (4th), A363499 (5th).

Programs

  • Mathematica
    Table[(n + 1) #^4 - (1/30) # (# + 1)*(20 #^4 + 4 #^3 - 14 #^2 + 4 # + 1) &[Floor@ Sqrt[n]], {n, 0, 45}] (* Michael De Vlieger, Jun 10 2023 *)
  • Python
    from math import isqrt
    def A363498(n):
        return (m:=isqrt(n))**4 *(n+1) - (m*(m+1)*(20*m**4+4*m**3-14*m**2+4*m+1))//30
    print([A363498(n) for n in range(0,46)]) # Karl-Heinz Hofmann, Jul 15 2023

Formula

a(n) = (n+1)*m^4 - (1/30)*m*(m+1)*(20*m^4+4*m^3-14*m^2+4*m+1), where m = floor(sqrt(n)).
Showing 1-3 of 3 results.